well its not going to help, as the sponsor you're suppose to have enough money to support her, so she will not need recourse to public funds
i take it this payment shows up on your bank statements, what does it say on the bank statement? does it mention loan etc? how much is your monthly payment ?
i don't remember on the visa app form asking you how much in debt you are, so depending on the amount being paid ??? i might not even mention it, but if its a lot, they might question what the payment is for